1. Field of the Invention
The present invention relates to metal treatment compositions for the lubrication of friction pairs.
2. Description of the Prior Art
Compositions for lubricating have long been used to prevent direct contact between surfaces of a friction pair. Much research has been done on various lubricant additives, sometimes called friction modifiers, to optimize the ability of the lubricating medium by reducing the coefficient of friction and decreasing the overall wear of the system. It is known in the art to use powders of soft metals such as Copper and Zinc, elements with low shearing bonds between layers such as graphite and disulphides, and polymer-based materials such as polytetrafluoroethylene to form protective films on the friction pair surfaces. These films promote improved tribological characteristics of the friction pair by preventing contact with the clean surfaces of the friction pair. A new direction in the field of lubricant additives points toward the use of members of the clay group of minerals. In these developments, dehydrated and pulverized clay are used as solid additives to the lubricant.
The Russian Patent 2,057,257 to Khrenov, et al., discloses a composition comprising; SiO, MgO, Fe2O3, FeO, Al2O3, and S having a particle size range of 0.01-1.0 micrometers. The treatment of this composition includes mechanical activation by aperiodic vibrations, but does not include any thermal processing. The U.S. Pat. No. 6,423,669 to Alexandrov et al. discloses a composition prepared from various minerals, which include several clays. The '669 patent teaches the use of the salts and oxides of the metals and non-metals comprising the raw minerals obtained by heating the clay at temperatures not less than 350 C.
Although the prior art discloses the use of pulverized and heated clay as an additive to a lubricant, the resultant composition does not contain or utilize the crystalline layer structure of the clay. Nor does the prior art utilize Tin (II) Chloride in their compositions. The compositions of the prior art comprise merely salts and oxides of the metals and non-metals of the clay. A composition that provides further decreases in coefficient of friction and overall system wear must be engineered.